Made the id generation stable across runtimes.

linkedin · Aug 17, 2023 · cf8bea2 · cf8bea2
1 parent d6ab13f
commit cf8bea2
Showing 1 changed file with 16 additions and 1 deletion.
diff --git a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/Utils.java b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/Utils.java
@@ -2,11 +2,14 @@
 
 import com.linkedin.avroutil1.compatibility.AvroCompatibilityHelper;
 import com.linkedin.avroutil1.compatibility.AvroVersion;
+import com.linkedin.avroutil1.compatibility.AvscGenerationConfig;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
 import java.security.CodeSource;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.regex.Matcher;
@@ -114,7 +117,19 @@ public static String fixSeparatorsToMatchOS(String path) {
   public static int getSchemaFingerprint(Schema schema) {
     Integer schemaId = SCHEMA_IDS_CACHE.get(schema);
     if (schemaId == null) {
-      schemaId = schema.toString().hashCode();
+      String schemaString = AvroCompatibilityHelper.toAvsc(schema, AvscGenerationConfig.CORRECT_ONELINE);
+      try {
+        MessageDigest md = MessageDigest.getInstance("MD5");
+        byte[] digest = md.digest(schemaString.getBytes());
+        int scratchPad = 0;
+        for (int i = 0; i < digest.length; i++) {
+          scratchPad = (scratchPad * 256 + (digest[i] & 0xFF));
+        }
+        schemaId = scratchPad;
+      } catch (NoSuchAlgorithmException e) {
+        schemaId = schemaString.hashCode();
+      }
+
       SCHEMA_IDS_CACHE.put(schema, schemaId);
     }